well obviously enjoy your slip and slide and then burn that fucker down
do it. what is the worst that can happen, you get written up? bfd.
when i was in the dorms we used to have huge ass water fights in the halls and the commons areas. we would also fill up trash bags with water and toss them out the windows from the third floor onto people walking to class.
finally we decided to have a battle royal in the basement late one night. we ended up destroying all the furniture, the big screen, pool tables, and the kitchen. they had to replace it all. and we didn't ever get in trouble.